/Engine/Plugins/MeshPainting/Source/MeshPaintingToolset/Public/MeshPaintingToolsetTypes.h
typedef TMulticastDelegate_FourParams< void, const [FMeshPaintParameters](API\Editor\MeshPaint\FMeshPaintParameters) &, const [FLinearColor](API\Runtime\Core\Math\FLinearColor) &, [FLinearColor](API\Runtime\Core\Math\FLinearColor) &, const float > FApplyVertexPaintData